Many persons are compelled to be fitted with catheters, either permanently or temporarily, for the excretion or drainage of the contents of the bladder. Such persons include incontinents, quadriplegics, stroke victims and hospital patients. Catheters are of two basic types; internal, directly to the bladder so that relatively small quantities of urine are emptied more or less continuously, or external, whereby relatively large quantities of urine are excreted from time to time. In either case, flow of the liquid into the container must be unimpeded and backflow must be avoided.
The problems and dangers inherent in catheterized urine drainage and storage systems are well known. Thus, for example, blockage of forward flow can result in stagnation, bacterial growth and infection. Backflow of already excreted urine can have similar dangerous results in addition to unpleasant accidental staining of clothing or bedding. Where the system includes a collecton bag worn by the user, problems of hygiene and odor are always present unless disconnection and cleaning of the bag and attachments are readily achievable.
Numerous efforts have heretofore been made to provide a valve that efficiently and inexpensively overcomes the problems alluded to, but without complete success. Perhaps the most widely used catheter-urinal valve is the construction commonly known as a flutter valve, comprising a substantially flat tube of relatively thin, elastic material. The typical simple flutter valve has a normal slit opening and, depending on the gauge and elasticity of the material, requires substantial back pressure to close it. Thus, for example, a wearer of a leg urinal who lies down or raises his leg toward the horizontal could experience the flow of collected urine back up through the open slit of the flutter valve.
A highly specialized form of flutter valve is shown in U.S. Pat. No. 3,463,159 comprising a surgical instrument for chest cavity drainage of liquids, solids and semi-solids, such as blood clots, tissue, and the like. That valve is of appreciable length (3 inches) and width (1 inch) and is so constructed that substances pass slowly therethrough in a sort of peristaltic action, apparently initiated by the breathing and build up of air pressure in the chest cavity of the patient. For reasons that will be evident to those skilled in the art, the patented valve would not be suitable for leg urinal use.
A more sophisticated urine collection valve is shown in U.S. Pat. No. 3,967,645. In that structure a complex molded sealing member includes a pair of flat parallel leaves having an upper funnel-like shape, an annular top flange and relatively thick side flanges. Rigid clips or the like are clamped over the side flanges for the ostensible purpose of closing the normally open passage between the leaves. The sealing member is then operationally positioned in a rigid body member by screwing an upper body member to grip the top flange and a low friction washer is employed to prevent distortion of the sealing member during assembly. In addition to being complex, with a number of separate elements, that valve required somewhat difficult and cumbersome manipulations to operationally position or remove the same.
There thus exists a need for a one-way valve for catheter associated urine collection systems that is substantially trouble free and foolproof, simple to install and remove and of so little expense that the same may be discarded and replaced as desired.